From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B789C4321A for ; Tue, 11 Jun 2019 14:39:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DE2822089E for ; Tue, 11 Jun 2019 14:39:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391382AbfFKOjj (ORCPT ); Tue, 11 Jun 2019 10:39:39 -0400 Received: from foss.arm.com ([217.140.110.172]:34638 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389484AbfFKOji (ORCPT ); Tue, 11 Jun 2019 10:39:38 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C398E337; Tue, 11 Jun 2019 07:39:37 -0700 (PDT) Received: from [0.0.0.0] (e107985-lin.cambridge.arm.com [10.1.194.38]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 603B13F557; Tue, 11 Jun 2019 07:39:36 -0700 (PDT) Subject: Re: [PATCH HACK RFC] cpu: Prevent late-arriving interrupts from disrupting offline To: paulmck@linux.ibm.com Cc: Mark Rutland , Peter Zijlstra , tglx@linutronix.de, mingo@kernel.org, jpoimboe@redhat.com, mojha@codeaurora.org, linux-kernel@vger.kernel.org References: <20190602011253.GA6167@linux.ibm.com> <20190603083848.GB3436@hirez.programming.kicks-ass.net> <20190603114455.GA16119@lakrids.cambridge.arm.com> <20190604074549.GP28207@linux.ibm.com> <6eb5d59f-37d0-0aab-1fc0-fcf48cc4164f@arm.com> <20190608164158.GK28207@linux.ibm.com> <16a424d1-0ab7-7e81-5c4f-93da23519b1d@arm.com> <20190611135429.GH28207@linux.ibm.com> From: Dietmar Eggemann Message-ID: <89ba6366-5be3-736e-ee78-3d9510aa2576@arm.com> Date: Tue, 11 Jun 2019 16:39:34 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20190611135429.GH28207@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/11/19 3:54 PM, Paul E. McKenney wrote: > On Tue, Jun 11, 2019 at 03:14:54PM +0200, Dietmar Eggemann wrote: >> On 6/8/19 6:41 PM, Paul E. McKenney wrote: >>> On Tue, Jun 04, 2019 at 03:29:32PM +0200, Dietmar Eggemann wrote: >>>> On 6/4/19 9:45 AM, Paul E. McKenney wrote: >>>>> On Mon, Jun 03, 2019 at 03:39:18PM +0200, Dietmar Eggemann wrote: >>>>>> On 6/3/19 1:44 PM, Mark Rutland wrote: >>>>>>> On Mon, Jun 03, 2019 at 10:38:48AM +0200, Peter Zijlstra wrote: >>>>>>>> On Sat, Jun 01, 2019 at 06:12:53PM -0700, Paul E. McKenney wrote: >>>>>>>>> Scheduling-clock interrupts can arrive late in the CPU-offline process, [...] >> Tested your patch on top of v5.2-rc4* on Arm TC2 (32bit) and CPU >> hotplug stress test. W/o your patch, the test fails within seconds >> since CPUs are not coming up again. W/ your patch, the test runs for >> hours just fine. >> >> You can add my: >> >> Tested-by: Dietmar Eggemann > > Thank you!!! > >> * just for the record: one additional unrelated patch (to disable >> the NOR flash) is necessary on Arm TC2: >> https://patchwork.kernel.org/patch/10968391 . > > Is this progressing, or does it also need help getting to mainline? This is an unrelated specific issue w/ the TC2 platform which will progress independently. Other Arm32 platforms should profit from your patch independently of that. I just wanted to mention it here in case people try to recreate the test on this specific platform. > Left to myself, I will push my patch and assume that the NOR flash patch > will make it in its own good time -- or, alternatively, that there is > someone better positioned than me to push it. IMHO, the best thing is you push your patch.